Tear-off closure with reinforcing rib

ABSTRACT

A tear-off closure is provided which has a top end wall and a depending skirt and having a tear strip defined by scoring divisive of the end wall and into the skirt, the tear strip having at least one embossed rib therein which extends from a location toward the center of the closure radially outward to a location adjacent the shoulder of the closure between its end wall and the skirt to ensure severance of the tear strip over such shoulder of the closure. The closure may further have a raised rim around a recessed central panel in its top end wall, with the rib in the tear strip extending from the recessed central panel into the rim of the closure.

United States Patent [191 Willis et all TEAR-OFF CLOSURE WITHREINFORCING RIB [75] Inventors: WiIburn C. Willis, Richmond, 1nd.;

Robert L. LaBal-ge, Ben Avon, Pa.

[73] Assignee: Aluminum Company of America, Pittsburgh, Pa.

[22] Filed: Mar. 5, 1971 [21] Appl. No.: 121,467

[52] US. Cl. 215/46 A, 220/54 [51] Int. Cl B6511 43/02 [58] Field ofSearch 215/46 A; 220/54,

[56] References Cited UNITED STATES PATENTS 3,556,336 1/1971 Coop 215/46A [451 July 3,1973

Primary Ekaminer-GeorQe T. Hall Atlorney-David W. Brownlee 5 7 ABSTRACTA tear-off closure is provided which has a top end wall and a dependingskirt and having a tear strip defined by scoring divisive of the endwall and into the skirt, the tear strip having at least one embossed ribtherein which extends from a location toward the center of the closureradially outward to a location adjacent the shoulder of the closurebetween its end wall and the skirt to ensure severance of the tear stripover such shoulder of the closure. The closure may further have a raisedrim around a recessed centralpanel in its top end wall, with the rib inthe tear strip extending from the recessed central panel into the rim ofthe closure.

9-Claims, 10 Drawing Figures PATENIEIJJUL 3191a 3.743.129

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INVENTORS. W/LBURN C. WILL/5 8 ROBERT L. LABARGE QMW AI forney TEAR-OFFCLOSURE WITH REINFORCING RIB BACKGROUND OF THE INVENTION It is known toprovide a tear-off closure which has a tear strip across its end walland into its skirt, and a pull tab attached to the tear strip as isshown in LaBarge et al. US. Pat. No. 3,441,163 and Schay US. Pat. No.3,353,739. Such closures frequently include means such as a recessedpanel in the end wall and a rim around the recessed panel to protect thetab from accidental opening. With this closure structure, there has beensome difficulty in ensuring that severance of the tear strip will followthe score line over the rim of the closure between its end wall andskirt. The rim of the closure produces a resistance to rupture of thescore line which may result in premature severance of the tear stripfrom the closure. An attempt was made to correct this problem byproviding an upwardly embossed island in the tear strip adjacent to, butnot extending into, the rim of the closure toform a lever in the tearstrip. Although this embossed island improved the openingcharacteristics of the closure, the closure was not completelyfoolproof. In some cases, the tear strip would be severed from theclosure at the top of SUMMARY OF THE INVENTION This invention provides atear-off closure which has a tear strip across its end wall and into itsskirt, and which has at least one embossed rib in the tear stripstarting in a center portion of the closure and extending outwardly to alocation adjacent the shoulder of the closure between its end wall andskirt to aid in severing the tear strip over the corner of the closureand form a partially split closure member which can be lifted from thecontainer.

Accordingly, an object of the invention is to provide an improvedtear-off closure which eliminates the problem of premature separation ofthe tear strip from the closure.

Another object of the invention is to provide a closure which has atleast one embossed rib in its tear strip to aid in severing the tearstrip over the corner of the closure.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects andadvantages of the invention will be further understood and appreciatedwith reference to the following description and drawings attachedthereto wherein;

FIG. 1 is a top plan view of a closure of the invention on a container;

FIG. 2 is a partial elevation view of the closure and container of FIG.1;

FIG. 3 is a partial cross-sectional view of the closure and container ofFIG. 1 taken along line III-III;

FIG. 4 is a partial cross-sectional view of the rib in the closure ofFIG. 1 taken along line IV-IV;

FIG. 5 is a partial perspective view of the closurecontainer combinationshowing partial opening of the closure;

FIG. 6 is a partial cross-sectional viewsimilar to FIG. 5 showingfurther severance of the tear strip;

FIG. 7 is a top plan view of an alternative form of closure of theinvention;

FIG. 8 is a partial cross-sectional view of the closure and container ofFIG. 7 taken along line VIII-VIII;

FIG. 9 is a partial cross-sectional view of a rib in FIG. 7 taken alongline IX--IX; and

FIG. 10 is a partial vertical cross-sectional view of theclosure-container of FIGS. 7 and 8 showing severance of the tear strip.

DESCRIPTION OF PREFERRED EMBODIMENTS In the several illustrationsappended hereto, metal closures or closure fitments are shown in theform of permanently deformable drawn metallic shells each of which has atop portion and a depending skirt terminating in a circumferential bead,and having a tear strip with a lever type pull tab affixed theretodivisive of the closure fitment to facilitate removal of the fitment. Acup-shaped liner of a resilient plastic material may be provided withinsuch a fitment to form a closure assembly. A container with entrancemouth is illustrated as a conventional open top jar, bottle, or thelike, made of glass, plastic or like material, and suited to have such aclosure assembly affixed thereto.

Referring to the illustrations, FIGS. 1, 2 and 3 show a a closurefitment 10 formed from sheet metal or other permanently deformablematerial, and preferably from a thin sheet of aluminum or an alloythereof, which is adapted to be secured over the entrance mouth of acontainer 12. Closure fitment 10 is comprised of a top end wall 14 and adepending skirt 16 terminating in a circumferential bead 18. The closurefitment 10 is weakened or scored along line 20 to form or define a tearstrip 22 divisive of the closure top from a starting location adjacentor towards the periphery of the top relative to its center, to agenerally opposite location, and from there divisive of the closurefitment along one side of the tear strip 22 all the way to the edge ofthe sheet material of the fitment, and along the other side of the tearstrip 22 to a location short of the edge of the sheet material leaving abridge or ligament of unscored metal between its end and the bottom ofthe skirt 16. The closure fitment 10 may also be scored outwardly of andadjacent to the starting end of the tearing strip 22 by means of twoscores 24. Scores 24 intersect the primary score 20 on opposite sides ofthe apex of the tear strip 22, and extend from the primary scoreoutwardly to the shoulder or corner between the end wall 14 and theskirt 16 of the closure. Alternatively, a single score could be providedwhich intersects the primary score 20 at or near the apex of the tearstrip and which extends outwardly to the skirt of the closure. Fitment10 may further include a downwardly embossed circular depression 26 inwhich a tab 30 may be seated and a number of upwardly embossed arcuateribs 28 on end wall 14 around its periphery to facilitate stackingcontainers on top of one another, and to protect the tab from accidentalopening of the closure.

Pull tab 30, illustrative of the type of tab that may be employed, isattached to the tear strip 22 in its starting end by means of anintegral rivet 32. Pull tab 30 is a reverse acting, double-lever typehaving a centrally open ring body 34 with a tongue 36 for affixation ofthe rivet 32. The tongue 36 is bendable at its junction with the tabbody 34 so that the tab can be easily initially lifted from the surfaceof the fitment top for severance of the tear strip 22. As affixed to thetear strip, the tab 30 lies substantially flush with the surface of thebottom wall of depression 26, and ribs 28 protect the opening structurefrom accidental opening or rupture of the score lines.

A liner 38 may be provided within the fitment for effecting a seal whenthe assembly is affixed to a container 12, and may serve as a reclosurefor the container after opening. Liner 38 may be formed from any of avariety of materials such as rubber, paper, cardboard, or a syntheticplastic such as polyethylene, polypropylene or polyvinyl chloride. Liner38 has a complete spanning top portion including a recessed centralpanel 40 and a raised rim 42 with a skirt 44 depending therefrom, and isdimensioned to fit or nest in closure fitment 10. An upwardly opengroove 45 may be provided on the closure skirt for engagement of fitmenthead 18 so that an assembly of the fitment and liner will not separateduring handling prior to affixation to a container.

The container mouth entrance illustrated in FIGS. 3 and 6 isrepresentative of a structure suitable for affixation of a closurefitment 10 and liner 38. It will be observed that container 12 providesan entrance mouth defined by an outwardly projecting closure securinghead 46 having an upwardly facing sealing surface, a laterally facingside sealing surface and a shoulder having an undersurface blending intothe container wall therebelow.

In the embodiment illustrated in FIGS. 1-6, tear strip 22 has anupwardly embossed rib 48 centrally located therein which extends fromcentrally in an essentially fiat top end wall 14 outwardly to a locationadjacent the corner of the fitment between its end wall and skirt tostructurally strength the tear strip during opening. As shown in FIG. 4,rib 48 has a generally arcuate transverse cross section, and extendsoutwardly at least to, and preferably beyond, a chordal line X-X drawnthrough the intersections of score line with the corner of the closurebetween the end wall 14 and the closure skirt 16 (FIG. 1). Rib 48 incombination with the curved arc of the closure skirt between the twolegs of score 20 reinforces tear strip 22 to substantially eliminatebending of the tear strip between the end wall and skirt of the closureduring opening. Bead 18 around the bottom edge of the closure skirt alsohelps to reinforce tear strip 22 and prevent bending of the tear stripduring opening. By eliminating bending of the tear strip during opening,rib 48 greatly facilitates severance of the tear strip over the cornerof the closure.

In prior art closures which had tear strips which were not reinforcedagainst bending at the corner between the top end wall and skirt of theclosures, the tear strips would sometimes bend at the corner of theclosure during opening and this would subject the metal in the tearstrip in the immediate area of severe bending to much higher thanaverage bending stresses. Such excessively high localized bending tendto weaken the metal along the line of bending in the tear strip, so thatwhen they are superimposed on top of the normal tensional stressesinduced in the tear strip during opening the path of tearing may bedirected inwardly of the score into the tear strip to cause prematureseverance of the tear strip. However, with rib 48 extending at least tochordal line X-X in a closure of the invention, bending of the tearstrip 22at the corner of the closure is substantially avoided and thecreation of excessively high localized bending stresses in the tearstrip is substantially avoided. Tear strip 22 may flex slightly duringopening, but the central portion of tear strip remains substantiallyrigid against bending. By avoiding bending and excessively highlocalized bending stresses in tear strip 22, premature severance of thetear strip is avoided. Metal fitment 10 is ruptured along score 20 as itdesired rather than rupture the unscored metal in the tear strip betweenthe score lines. Accordingly, severance of tear strip 22 will convertclosure fitment 10 into a partially split member which can be easilyremoved from a container as will be described.

To open a container having a closure of the invention affixed thereto,the free end of the pull tab 30 is lifted to fulcrum the tab about apoint outwardly of score line 20, causing tongue 36 on the tab to bendor flex at its juncture with the tab body and exert an upward force onrivet 32 and tear strip 22. This causes initial rupture of score 20around the attachment rivet at the starting end of, the tear strip.After initial rupture of score 20 around the starting end of tear strip22, continued pulling of tab 30 ruptures the score along both sides ofthe tear strip into the closure skirt 16. During such rupture, rib 48reinforces the portion of the tear strip in which it is located andmaintains the tear strip as a substantially rigid member as shown inFIG. 6, although it may flex slightly between the top end wall 14 andskirt 16 of the closure. Initially, rib 48 may fulcrum or pivot aboutits outer end adjacent the corner of the closure as permitted by theresilience and slight flexing of the tear strip at such corner. However,the tear strip is quickly flexed to its maximum as limited by rib 48 andby the curved skirt portion in the tear strip, and the point offulcruming moves to bead 18 on the bottom edge of the tear strip asillustrated in FIG. 6 to rupture score 20 down the closure skirt. Duringsuch fulcruming of the rigid portion of tear strip 22, score 20 alongboth sides of the tear strip is subjected to an almost optimumcombination of shear and tension which ensures that the tear strip isnot prematurely severed from the closure at the corner between its topend wall'14 and skirt 16.

As tab 30 is pulled, tearing stops at the end of the short leg ofscoring in the skirt of the closure, but continues along the length ofthe other leg of scoring which preferably extends all the way to theedge of the skirt through bead 18 to convert the closure into a stillunitary, partially split member with the tear strip attached to theskirt of the closure fitment by a ligament or bridge of metal betweenthe end of the short leg of scoring and the bottom of the skirt. Thisresults in confronting ends of the severed sectors of the closurefitment. Spreading such confronting ends will rupture at least one ofthe scores 24 adjacent the starting end of the tear strip and causehinge-like opening of the closure without dismemberment thereof. Theclosure can then be lifted from the container leaving liner 38 which canbe removed with ones fingers.

Referring to FIGS. 7, 8, 9 and 10, an alternative embodiment of theinvention is illustrated in the form of a sheet metal closure fitment 50which is adapted to be secured over the entrance mouth of a container52. Closure fitment 50 is comprised of a spanning top portion or endwall with a recessed central panel 54, a raised rim 56 around thecentral panel, and a depending skirt 58 terminating in a circumferentialbead 60.

Central panel 54 includes an incline 62 at its periphery which connectscentral panel 54 and rim 56. Closure fitment 50 is weakened or scoredalong line 64 to define a tear strip 66 divisive of the closure top froma starting location adjacent or towards the periphery of the toprelative to its center, to a generally opposite location, and from theredivisive of the closure fitment along one side of the tear strip 66 allthe way to the edge of the sheet material of the fitment, and along theother side of the tear strip to a location short of the edge of thesheet material leaving a bridge or ligament of unscored metal betweenits end and the bottom of the skirt 58. The closure fitment 50 may alsobe scored outwardly of and adjacent to the starting end of the tearstrip 66 by means of two scores 68 which intersect the primary score 64on opposite sides of the apex of the tear strip, and extend from theprimary score outwardly to the shoulder between the rim 56 and the skirt58 of the closure.

A pull tab 70 similar to the one that was shown on the closureillustrated in FIGS. 1-6 is attached to the tear strip 66 in itsstarting end by means of an integral rivet 72. Pull tab 70 is a reverseacting, double-lever type having a centrally open ring body 74 with abendable tongue 76 for affixation of the rivet 72. As affixed to thetear strip, the tab 70 lies substantially flush with the surface of therecessed panel 54, and closure rim 56 protects the tab 76 and score 64from accidental rupture.

A liner 78 may also be provided within fitment 50 for effecting a sealwhen the assembly is affixed to a container 52, and may also serve as areclosure for the container after opening. It has a complete spanningtop portion including a recessed central panel 80 and a raised rim 82with a skirt 84 depending therefrom, and is dimensioned to fit or nestin closure fitment 50. The bottom of the liner skirt 84 may include anupwardly open groove 85 for engagement of container bead 60 so that anassembly of the fitment and liner will not separate prior to applicationto a container.

The container mouth entrance illustrated in FIG. 8 is similar to thatillustrated in FIG. 3, and is defined by an outwardly projecting closuresecuring bead 86 having an upwardly facing sealing surface, a laterallyfacing side sealing surface, and a shoulder having an undersurfaceblending into the container wall therebelow.

In the embodiment shown in FIGS. 7-10, tear strip 66 has three upwardlyembossed ribs in it which extend from central panel 54 into raised rim56 around the central panel to structurally strengthen the tear stripduring opening. The three ribs comprise a center rib 88 extending from acentral portion of the container end wall into the rim of container, andtwo short ribs 90, one of either side of the center rib 88, which alsoextend from the recessed central panel 54 into the rim of the closure.As shown, the two shorter ribs 90 may diverge from the center rib 88toward the periphery of the closure to form a rigid triangular-shapedzone in the closure. Referring to FIGS. 8 and 9, ribs 88 and 90 areinclined upwardly from the recessed central panel 54 to the area of therim 56 and have generally arcuate transverse cross sections as did therib of FIG. 4.

All three ribs in the tear strip 66 preferably extend outwardly to, andpreferably beyond, a chordal line X-X drawn through the intersections ofscore line 64 and the comer of the closure between rim 56 and skirt 58..By extending the ribs 88 and 90 at least to chordal line X-X, the ribs,in combination with the closure skirt, will reinforce the tear strip sothat it can bend very little if any as it is severed over the rim of theclosure. As a result, the creation of excessively high, localizedbending stresses in the metal in tear strip 66 is substantially avoided.This ensures that the metal in the fitment is ruptured along score lines64 as is desired rather than rupture the unscored metal in the tearstrip. Bead 60 around the bottom edge of the closure skirt also helps toreinforce the tear strip and ensures that the tear strip is notcompletely severed from the closure.

To open a container having a closure of the invention affixed thereto,the free end of pull tab 70 is lifted to fulcrum the tab about a pointoutwardly of score line 64, causing tongue '76 on the tab to bend orflex at its juncture with the tab body, and exert an upward force onrivet 72 and tear strip 66. This causes initial rupture of score 64around the attachment rivet at the starting end of the tear strip. Afterinitial rupture of score 64, continued pulling of tab 70 ruptures score64 along both sides of the tear strip into the closure skirt 58. Duringsuch rupture, ribs 88 and 90 reinforce the portion of the tear strip inwhich they are located and maintain the tear strip as a substantiallyrigid member as shown in FIG. 6. This places the score 64 along thesides of tear strip 26 in an almost optimum combination of shear andtension, and ensures that the tear strip is not prematurely severed fromthe closure at rim 56.

As tab 70 is pulled, tearing stops at the end of the short leg ofscoring in the skirt of the closure, but continues along the length ofthe other leg of scoring which extends all the way to the edge of theskirt through bead 20 to convert the closure into a still unitary,partially split member with the tear strip attached to the skirt of theclosure fitment by a ligament or bridge of metal between the end of theshort leg of scoring and the bottom of the skirt. This unitary,partially split member can then be removed from the container as wasdescribed with respect to the closure illustrated in FIGS. 1-6.

It will be apparent to those versed in the art to which the invention isaddressed that particular embodiments have been selected for purposes ofspecific illustration and description, but that numerous variations canbe made in the structural details of the selected embodiments withoutdeparting from the invention.

What is claimed is:

1. In a sheet metal closure having a top end wall and a depending skirtwith a tear strip divisive of the top end wall and extending into theskirt, and further having a tab attached to the starting end of the tearstrip, the improvement comprising at least one embossed rib in the tearstrip extending from a central portion of the end wall outwardly atleast to a chordal line drawn across the top of the closure through theintersections of the sides of the tear strip with the corner of theclosure between its end wall and skirt to form a rigid section in thetear strip to resist bending thereof between the end wall and skirt ofthe closure whereby severance of the tear strip over the corner of theclosure is facilitated.

2. A closure as set forth in claim 1 in which said rib is upwardlyembossed.

3. A closure as set forth in claim 1 which includes a curled bead on thebottom edge of the closure skirt.

4. A closure as set forth in claim 1 in which said tear strip is definedby a U-shaped score having one leg which extends to the bottom edge ofthe closure skirt and a second leg which terminates short of the bottomwardly embossed ribs extending from the recessed central panel into therim of the closure.

8. A closure as set forth in claim 7 in which said ribs extend outwardlyat least to a chordal line drawn across the top of the closure throughthe intersections of the sides of the tear strip with the corner of theclosure between its rim and skirt.

9. A closure as set forth in claim 7 including a center rib whichextends from a central portion of the closure into the rim and twoshorter ribs, one on either side of said center rib and diverging fromthe center rib as they extend toward the periphery of the closure.

1. In a sheet metal closure having a top end wall and a depending skirtwith a tear strip divisive of the top end wall and extending into theskirt, and further having a tab attached to the starting end of the tearstrip, the improvement comprising at least one embossed rib in the tearstrip extending from a central portion of the end wall outwardly atleast to a chordal line drawn across the top of the closure through theintersections of the sides of the tear strip with the corner of theclosure between its end wall and skirt to form a rigid section in thetear strip to resist bending thereof between the end wall and skirt ofthe closure whereby severance of the tear strip over the corner of theclosure is facilitated.
 2. A closure as set forth in claim 1 in whichsaid rib is upwardly embossed.
 3. A closure as set forth in claim 1which includes a curled bead on the bottom edge of the closure skirt. 4.A closure as set forth in claim 1 in which said tear strip is defined bya U-shaped score having one leg which extends to the bottom edge of theclosure skirt and a second leg which terminates short of the bottom ofthe skirt.
 5. A closure as set forth in claim 1 in which said top endwall is substantially flat and said rib is substantially equidistantbetween the sides of the tear strip.
 6. A closure as set forth in claim5 in which said top end wall includes a circular depression in whichsaid tab is seated.
 7. A closure as set forth in claim 1 in which saidtop end wall includes a recessed central panel with a raised rimtherearound and the tear strip includes three upwardly embossed ribsextending from the recessed central panel into the rim of the closure.8. A closure as set forth in claim 7 in which said ribs extend outwardlyat least to a chordal line drawn across the top of the closure throughthe intersections of the sides of the tear strip with the corner of theclosure between its rim and skirt.
 9. A closure as set forth in claim 7including a center rib which extends from a central portion of theclosure into the rim and two shorter ribs, one on either side of saidcenter rib and diverging from the center rib as they extend toward theperiphery of the closure.